The primary aim of this proposal is to identify factors that contribute to healthy aging and exceptional longevity in man. With optimal environments and behaviors, an average person has the ability to live to around age 85. Centenarians on the other hand live 15-25 years beyond what might be considered average. Many escape lethal diseases associated with aging (Alzheimer's disease, stroke, cancer, cardiovascular disease, and diabetes) or their age of onset is delayed. In order to live to such old age, centenarians are less likely to have genetic and environmental exposures that would cause at least lethal diseases at younger ages. We propose to study a cohort of centenarians and control subjects who were recruited by the New England Centenarian Study. We have selected a series of genes to study that have been shown to determine longevity in multiple model systems including C. elegans, D. melanogaster and mice. The genes include members of the insulin-like growth factor signaling pathway and the sirtuin cell signaling system. This pathway is critical for induction of enzymes and proteins involved in protecting organisms from reactive oxygen species which, when present in high amounts, can have a deleterious effect on cell and tissue health. Overall, the discovery of these pathways and their interrelationships have been key findings in longevity research that connects a large number of factors that are known to be important in longevity including disease pre- disposition, developmental factors, metabolism, environment, oxidant stress and tissue damage. As a result of our first funding cycle, we have definitively validated the hypothesis that genes in the insulin signaling pathway are important genetic determinants of aging. In this competitive renewal, we propose to examine these genes in more detail and to identify the specific functional variants responsible for promoting longevity using modern sequencing technologies. In addition, we will utilize a series of in vitro functional studies to confirm that specific variants impact protein expression or protein function. In addition, these functional studies have the potential to identify novel and important variants that are missed when using a traditional case- control association study. Thus, the results of our work is not only contribute to understanding the factors that permit humans to live longer, but even more importantly, live longer without the disabling diseases associated with advanced age.